Blindstitch-sewing machine



Nov. 12, 1929. PRESTWICH- 1,735,584

BLINDSTITCH SEWING MACHINE Filed Aug. 9, 1926 5 Sheets-Sheet 1 INVENTORd ATTORNEY Nov. l2, 1929. F1. PRESTWICHK' 1,735,584

BLINDSTITCH SEWING MACHINE Filed Aug. 9, 1.926 5 Sheets-Sheet 2 INVENTORATM ATTORNEY W29. F. M. PRESTWECH BLINDSTITCH SEWING MACHINE Filed Aug.9. 1926 5 Sheets-Sheet 3 INVENTOR A TTORNE Y Nov. 12, 1929. F. M.PRESTWICH BLINDSTITCH SEWING MACHINE Filed Aug. 9, 1926 5 Sheets-Sheet 4INVENTOR.

ATTORNEYS.

Nov. 12, 1929.

F. M. PRESTWICH BLINDSTITCH SEWING MACHINE Filed Aug. 9. 1926 5Sheets-Sheet 5 INVENTOR M L W BY I ATTORNEIY M. PRESTWI, OF NEW YQEK, N.i.

BLIND'S'EITCH-fiING, EAGHINE Application. filed August 9, 1923. SerialNo. 128,013.

This invent-ion relates to blind stitch sewing machines, and has for itsobject to provide a machine which is capable of working upon a widevariety of materials including both fine and thick fabrics, as well asmaterials of a non-uniform thickness.

. A well known form of blind stitch machine comprises a curved needlemovable through the under fabric and then diagonally through theoverlying material with a fabric bender located beneath the goods andadapted to raise the goods into co-operation with the needle. Anobjection to this type of machine is the inability to satisfactorilyoperate upon materials of non-uniform thickness, such as a coat sleevelining at the arm hole which has more padding in one part than in another, also the-top of waisthands of trousers where beltloops andbuttons are encountered. With the bender located'heneath the material,set togive a predetermined thrust, a larger protrusion or dome is formedwith thick material than with thin, and therefore since the diameter ofprotrusion with thick material is greater than with thin, the needie hasa longer stroke through the goods, the result that it may be too greatto form a proper or even stitch it the mamriai is of nonnniiormthickness.

according to this invention, a picker is provided instead or" thebender-of the prior ar and the picker is located to penetrate the:ZQWQE' .iahric top and move in lrnedreiatien to the needie forpenetration thereby preciseiy as the first movement in i and sewing.Since the picker enters the top o he mate ,'in the vicinity of the pathof the needie,

snakes i "do or no difference whether ork he thich or thin, or orvarying r the bottom face or? the stationary at arms the dete line r themateto be sewn. yieldahle weri: support is 9 d take care of largerirregnlariti" work and the top surface or he made flexible to udden"inor irreguiarities were: thickness. ieidaioie work support wilt cssthe worn: evenly against the ont 142i sect: of the feet regardless ofvarying thickness of work and the top surface of the work will at alltimes be on a definite line between front and back surface of the footand in precisely the correct register for the picker needle to strikethrough the opening in. the foot. The movement of the picker isadjustable for difi'erent conditions, to obtain different lengths anddepths of thrust. The machine of this invention has a greater held ofusefulness than prior art machines now commercially used as it isadaptable foruse with heavy overcoats or with the hemming at the bottomof a thin satin skirt.

Referring to the drawings:

Fig. l is an elevation partly in section of a blind stitch sewingmachine embodying this invent-ion,

Fig. 2 is a left end view of the device of Fig. 1,

Fig. 3 is a section on the line c-c oi? Fig. 1.

Fig. t is a section on the line dzi of Fig. 1.

Fig. 5 is a section on the line e-e of Fig. i.

Fig. 6 is a section on the time f-f of Fig. i.

Fig. '3 illustrates the form of machine in which the picker needle doesnot move back and forward with the feed dog.

Fig. 8 is a longitudinai section of the work support on line it-h shownin 9 shows another type of work support. a re is stop plan viewot yetanother construction for the work support.

5 11 is a longitudinal section of the work sort oi on iine thereof.

' is View corresponding to d,

i owned construction.

a rear the device F 14: is a rear view of the device of with the sewingneedie removed.

1s customary in hnnd stitch sewing machines, the power. is supphed tothe strait Ill. I

the work. passing beneath the presser foot 18 hun from the dependingsupport 19. A0-

cor mg to common practlce, the presser foot is recessed to permit a feeddog to engage the work, and is also provided with a usual edge guide andprojection for raising the edge of the work. Beneath the presser foot isthe work support 20 shown in Fig. 1, being pivotally mounted on the rod21 through the supporting column 22 through which passes the pin 23 fortransversel pivoting the frame 24 for the yieldable work support 26,which is rotatable in the bearings 25' of said frame. As shown in Figs.1 and 5, the yieldable work support 26 comprises resilient prongs 27 and28 extendingalternately from opposite sides of the rotatable member 26.In this way, irregularities in thickness of the work passing over thetop central portion of the resilient work support 26 may be compensatedfor by bending of the prongs 27 and 28.

Larger irregularities may be taken care of by yielding of the supportingmember 29 agamst the action of sprmg 30. Owing to the pivotal mountin ofthe yieldable work support 26, the ,mem er 26 as a whole may tilt tocompensate for the presence of irregularities in thickness of the worktransversely of the path of movement of the work through the machine.-Theplate 31 shown in Figs. 1 and r 5 is provided with a large recessthrough which the ieldablework support 26 co-operates with t e work.

Also mounted on the shaft 10 is the gear 32 engaging another gear 33 onshaft 34 driving 'the bevel gear 35 and its co-operating bevel gear onthe shaft 36. As shown in Fig. 3 the bevel gear'35 is blanked throughouta portion of 1ts circumference so a to only intermittently actuate theshaft 36 in timed relation to the movement of the main shaft 10 andneedle 15. On the lower end of shaft 36 is another bevel gear'37actuating the cooperating gear 38 on shaft 39 within the hearing 40 fordriving the rotatable member 41 provided with a slot 42 as shown inFigs. 1 and 6. Adjustably mounted within this slot 42 is the pin 43passing through one end of the connecting bar 44 having the pickerneedle 45 mounted at ,,its other end. This picker needle isso locatedand actuated as to'engage the work in timed relation to movement of theneedle 15 and move the work to suflicient height to be engaged" by. theneedle 15'. Within the connecting bar 44 is the slot 46 having the pivotpin 47 passing therethrough and on which the connecting bar44 ismounted. The

pivot pin 47 is slidable within its supporting bearing in bracket 48with the backward and forward movement of the feed dog. A wingnut 49adjustably controls the height of the bracket 48 which is slotted at 50for this purpose. The feed dog 53 has an extension 52 provided withbifurcated ends 51 engaging a threaded member on the pivot pin 47 forgivin this pin and likewise the picker needle 45 a forward and backwardmovement with the feed dog. Simultaneously member 41 raises and lowersthe picker needle in properly timed relation to the movement of thestitching needle 15, so that the picker needle has both u and downmovement and backward and orward movement. As shown in Fig. 5 thepresser foot is recessed to enable the picker needle 45 to co-operatewith the work. Also in Fig. 5 alternate parallel and angular movementsof the stitching needle 15 are represented by the dotted lines 54. Thefeed dog as is customary is actuated by a pair of eccentrics shown inFig. 1 on shaft 10, one for giving it the forward and'back wardmovement, the other the up and down motion. For controlling the angularrelationship between gear 33 and shaft34 for accurately timing thepicker needle, the shaft 34 is provided with the projection'55 thereon,and secured to the gear 33 are the projections 56. Adjustable threadedmembers pass through the projections 56 and engage the projectionenabling the shaft to be relatively rotated a slightamount with respectto the gear 33, the gear 33 being otherwise free on the shaft anddriving the shaft 34 through projections 55 and 56, as shown in Fig. 6.

Fig. 7 illustrates the preferred embodiment of this, invention, in whichthe picker needle does not have the forward and backward movement withthe feed dog; that is, there is no extension on the feed dog as in thereceding figure, but the picker needle ere does have its movementlaterally in the path of the goods as previously described in.

with the feed dog, but only has the rotary movement referred to.

Figs. 12 to 14 inclusive illustrate other views of the same preferredform of the invention that is shown in Fi 7.

The work support shown in Figs.'-7 and 8 comprises the recessed plate65, mountedon the supporting colunm 58 which. is yieldable under theaction of spring 64 to take care of large irregularities in thickness ofthe work. The springs 66, mounted on the cross bars, illustrated assthrough the recess in plate 65 and 811516 small irregularities inthickness of the work to be taken care of.

Fig. 9 illustrates a type of work su port in which the plate 62 is notrecessed and is yieldable only under the action of the spring 63.

Fig. 10shows another form of work sup- .port in which the plate 57isrecessed and the springs 60 constitute individually yields ablesupport members within the recess to take up irregularities in thethickness of thework, such as belt loops or buttons in sewing trouserwaistbands. Also, the tautness of the work throws extra thicknesses intothe space between. Each of the springs 60 is of general spiral shape asshown. Larger variations in thickness of the work are compensated for bythe spring 59, shown in Fig. 11.

Among the advantages of this invention may be mentioned the ability ofthe machine to operate on a wide variety of work, whether thin goods orthick material and with equal facility; The picker needle may engage thework at the side or on substantially its upper surface, so as to moveeither thin or thick material with equal ease. A special advantage ofthis machine is its adaptability to produce better work through havingthe stitches uniform when the work varies inthickness, as for example,in the upper attachment of the lining of a coat sleeve where the goodsare' not of uniform thickness due to more ,padding being used in someportions of the shoulder than in others. By loosening the nuts on shafts43 and 47, the bar 44 can be moved backward or forward to vary theeccentricity of shaft or pin 43 with respect to the rotatable disc orwheel 41. This vathe nut on shafts 43 and 47 can be tightened themachine, of a picker for penetrating t as well as the wing nut 49. Thebar 44 naturally will have a certain amount of movement with respect tothe shaft 47, but the shaft 47 does act as a fulcrum for the bar 44. Thedifferent types of yieldable work supports shown enable the goods tobepassed under the presser foot without interfering with the operationof the machine, and the location of the icker needle above the presserfoot or feeding means enables the work sup-- sign to suit any particularwork.

Provision may be made for using a picker a needle to penetrate the toplayer of the lining at eve stitch if desired.

1 claim:

1. lln a blind stitch sewing machine, the combination witha work supportand means for feeding two layers of material through superimposed layerand the upper surface of the base layer of the material and moving bothto a predetermined position, a curved needle positioned to similarlypenetrate the layers and form the stitch when the layers are so moved bythe picker and means for driving the feeding means, picker and needle insynchronism.

2. In a blind stitch sewing machine, the combination with a worksupport, a presser foot spaced therefrom to permit the passage of twolayers of material, and feeding means, of a picker for penetrating thesuperimposed layerand the upper surface of the base layer of thematerial and moving both to a predetermined position, a curved needlepositioned to similarly penetrate the layers and form the stitch whenthe layers are so moved by the picker, and means for driving the feedingmeans, picker and needle in synchronism.

3. In a blind stitch sewing machine, the combination with a worksupport, a presser foot spaced therefrom to permit the passage of twolayers of material, and feeding means, of a picker for penetrating thesuperimposed layers and the upper surface of the base layer of thematerial and lifting both from the work support to a predeterminedposit-ion, a curved needle positioned to similarly penetrate the layersand form the stitch when the layers are so lifted b the picker, andmeans for driving the feeding means, picker and needle in s'ynchronism.

4. In a blind stitch sewing machine,-the combination with a worksupport, of means for feeding the work through the machine, a needle,means for actuating the needle alternately parallel and at an angle tothe movementjof the work, a picker needle located adjacent the firstneedle and above the work support, means for actuating the picker needlein timed relation to the first needle for "penetrating and moving thework into the path of the first needle, and means to control the amountof material moved by the picker needle. I

5. In a blind stitch sewing machine, the combination with a worksupport, means for feeding the work through the machine,' a needle, andmeans for actuating the needle alternately parallel and at an angle tothe movement of the work, of a picker needle located adjacent the firstneedle and above the work support, and means for actuating the pickerneedle in timed relation with the first needle for penetratin and movingthe work into the path of the rst needle.

6. A blind stitch sewing machine comprising a work support, means forfeeding two layers of material through the machine,

1 picker means located above the work support for penerating thesuperimposed layer and the upper surface of the base layer of thematerial and lifting both from the work support,'a curved needlepositioned to similarly penetrate the layers to form the. stitch whenthe layers are so lifted by thepicker, a yieldable work engaging membersupported in said work support and means for driving the feeding means,picker means and needle in synchronism.

. 7. A blind stitch sewing machine comprising a needle, actuatingmechanism therefor,

a work support, means for feeding the work over the work support, pickermeans operated in timed relation to said needle to penetrate and movethe work into the path ofthe' needle, said work support comprising aflexible member for yieldlng under small irregularities in thickness ofthe work, and a yieldable support for said flexible member wherebylarger irregularities in thickness of the work are provided for.

8. A blind stitch sewing machine comprising a needle, actuatingmechanism therefor, a work support, means for feeding the work throughthe support, picker means located above the work and actuated in timedrelation to the needle for penetrating and moving the work forengagement by said needle, said work support comprising a flexiblemember 'for bending under small irregularities in thickness of the work,and a yieldable support for said flexible member whereby largerirregularities in thickness are provided for.-

9. In a blind stitch sewing machine, 'the combination with a worksupport, bf means for feeding work through the machine, a needle, meansfor actuating the needle, a picker needle located adjacent to the firstneedle and above the work support, means for actuating the picker needle1n timed relation to the first needle for penetrating and moving thework into the path of the first needle and means for adjusting themovement of said picker needle.

10. In a blind stitch sewing machine, the combination with means forfeeding the work theretlrrough, of a needle, actuating mechanismtherefor, means timed with the needle for penetrating the work above itslower surface and moving the work to intercept the needleand a yieldablework support beneath said needle.

' Signed at New York in the county of New York and State of New Yorkthis 2nd day of August, A. D. 1925.

FRANK M. PRESTWICH.

